The present study explored the impacts of Ile on muscle fatty acid and amino acid profiles,lipid metabolism,and autophagy in hybrid catfish.Seven isonitrogenous(387.8 g/kg protein)semi-purified diets were formulated to contain 5.0(control),7.5,10.0,12.5,15.0,17.5,and 20.0 g Ile/kg diet respec-tively.The fish(initial weight of 33.11±0.09 g)were randomly assigned to 7 groups for a 56-day trial.Each group has 3 replicates with 30 fish per replicate,fed at 08:00 and 18:00 each day.Results showed that muscle protein and lipid,C14:0,C18:0,C22:0,C14:1,C18:1n-9,polyunsaturated fatty acid(PUFA),Arg,Ile,Ala,Cys,Gly,Tyr,essential amino acid(EAA),and total amino acid(TAA)contents and flavor amino acid(FAA)/TAA in muscle had positive linear and/or quadratic responses to dietary Ile levels(P＜0.05).Fatty acid synthase(FAS),stearoyl-CoA desaturase(SCD),acetyl-CoA carboxylase(ACC),and lipoprotein lipase(LPL)activities had positive linear and/or quadratic responses,but carnitine palmitoyl transferase 1(CPT1)activity had a negative response with increasing dietary Ile levels(P＜0.05).The mRNA expressions of FAS,SCD,ACC,LPL,fatty acid binding protein 4(FABP4),FATP1,sterol response element-binding protein 1c(SREBP-1c),sequestosome 1(SQSTM1),and adenosine 5'-monophosphate-activated protein kinase(AMPK)had positive linear and/or quadratic responses to dietary Ile levels(P＜0.05).The mRNA expressions of hormone-sensitive lipase(HSL),CPT1,peroxisome proliferator-activated receptor α(PPARα),PPARy,uncoordinated 51-like kinase 1(ULK1),beclin1(Becn1),autophagy-related protein 9α(Atg9α),Atg4b,Atg7,autophagy marker light chain 3 B(LC3B),and SQSTM1 in muscle had negative linear and/or quadratic responses to dietary Ile levels(P＜0.05).The p-AMPK and ULK1 protein levels,and p-AMPK/AMPK were decreased by 12.5 g Ile/kg in the diet(P＜0.05).Finally,SQSTM1 protein level had the opposite effect(P＜0.05).The above results indicate that dietary Ile im-proves fish muscle fatty acid and amino acid profiles potentially via respectively regulating lipid meta-bolism and autophagy.The Ile requirement of hybrid catfish(33 to 72 g)were estimated to be 12.63,13.77,13.75,11.45,10.50,12.53 and 12.21 g/kg diet based on the regression analysis of protein,lipid,SFA,PUFA,FAA,EAA,and TAA muscle contents,respectively.

Ye Zhao;Xia Dong;Chang-Rui Guo;Lin Feng;Yang Liu;Wei-Dan Jiang;Pei Wu;Wei Luo;Xiao-Li Huang;De-Fang Chen;Xiao-Qiu Zhou;Jun Jiang

College of Animal Science and Technology,Sichuan Agricultural University,Chengdu 611130,China;Animal Nutrition Institute,Sichuan Agricultural University,Chengdu 611130,China;Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province,Sichuan Agricultural University,Ya'an 625014,China

动物营养（英文）

[1]Ye Zhao;Xia Dong;Chang-Rui Guo;Lin Feng;Yang Liu;Wei-Dan Jiang;Pei Wu;Wei Luo;Xiao-Li Huang;De-Fang Chen;Xiao-Qiu Zhou;Jun Jiang-.Dietary isoleucine affects muscle fatty acid and amino acid profiles through regulating lipid metabolism and autophagy in hybrid catfish(Pelteobagrus vachelli ♀×Leiocassis longirostris ♂))[J].动物营养（英文）,2022(04):369-380

catfish,Becn1,Atg9,Atg4b

Dietary,isoleucine,affects,muscle,fatty,acid,amino,profiles,through,regulating,lipid,metabolism,autophagy,hybrid,Pelteobagrus,vachelli,Leiocassis,longirostris,present,study,explored,impacts,Ile,Seven,isonitrogenous,semi,purified,diets,were,formulated,contain,control,initial,weight,randomly,assigned,groups,day,trial,Each,replicates,fed,each,Results,showed,that,C14,C18,C22,1n,polyunsaturated,PUFA,Arg,Ala,Cys,Gly,Tyr,essential,EAA,total,TAA,contents,flavor,FAA,had,positive,linear,quadratic,responses,dietary,levels,Fatty,synthase,FAS,stearoyl,CoA,desaturase,SCD,acetyl,carboxylase,ACC,lipoprotein,lipase,LPL,activities,but,carnitine,palmitoyl,transferase,CPT1,activity,negative,increasing,expressions,binding,FABP4,FATP1,sterol,element,1c,SREBP,sequestosome,SQSTM1,adenosine,monophosphate,activated,kinase,AMPK,hormone,sensitive,HSL,peroxisome,proliferator,receptor,PPARy,uncoordinated,like,ULK1,beclin1,related,Atg7,marker,light,chain,LC3B,decreased,by,Finally,opposite,effect,above,results,indicate,proves,potentially,via,respectively,requirement,estimated,regression,analysis,SFA

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